Page 49 - Sember, Vedrana, and Shawnda A. Morrison. 2018. The Mind-Body Connection. Koper: University of Primorska Press.
P. 49
Quantifying Physical Activity
tomized to one second or less. Shorter intervals, such as 15s epoch
is more suitable for shorter and more intensive movement, because
longer interval may not detect a short-lasting movement. Use of a
longer epoch does not give an accurate assessment of high intensity
activity, but longer epoch ensures longer data collection and stor-
age up to three weeks or more (Nilson, Ekelund, Yngve, & Sjostrom,
2002). The majority of the studies in children and adolescents used
a 60s epoch (66%) and 15s epoch in preschoolers (42.9%) (Cain, Sal-
lis, Conway, Van Dyck, & Calhoon, 2013).
A valid day is one of the conditions we need to take in considera-
tion when measuring with accelerometers. The valid day is defined
by a minimum number of wearing hours. Rule 70/80 provides that
70% of the sample subjects wear an accelerometer for at least 80%
of the daily observation time (Catellier et al., 2005). Minimum num-
ber of wearing accelerometer ranges from 3–10 days (Mattocks et
al., 2008), 7 days should be reasonable standard for all ages (Ward,
Evenson, Vaughn, Rodgers, & Troiano, 2005). One of these days
needs to be weekend day (Rowlands, 2007).
When measuring physical activity with accelerometers, we need
to define non-wear time within a day, which is normally identified
with summing consecutive zero counts per minute (cpm) and wear
time is computed by decreasing the non-wear time from cumulative
possible time. It is very important to differentiate between wearing
accelerometer but being sedentary and not wearing accelerometer
because of sleep time or swimming (Cain et al., 2013).
Pedometer is probably the oldest technique to assess physical activ-
ity and was designed by Leonardo da Vinci 500 years ago (Montoye,
Kemper, Saris, & Washburn, 1996). The pedometer records acceler-
ation and deceleration of movement in one direction (Saris & Bink-
horst, 1977). Pedometers provide measure of the number of steps
taken during a given period of time (Kohl et al., 2000). Pedomet-
ers have been used for measuring physical activity for the last two
decades. Advantage of pedometers is low-cost, effectiveness (Buck-
worth, Lee, Regan, Schneider, & DiClemente, 2007) and usefulness
particularly in the epidemiological studies (Volmut, 2014). Disad-
47
tomized to one second or less. Shorter intervals, such as 15s epoch
is more suitable for shorter and more intensive movement, because
longer interval may not detect a short-lasting movement. Use of a
longer epoch does not give an accurate assessment of high intensity
activity, but longer epoch ensures longer data collection and stor-
age up to three weeks or more (Nilson, Ekelund, Yngve, & Sjostrom,
2002). The majority of the studies in children and adolescents used
a 60s epoch (66%) and 15s epoch in preschoolers (42.9%) (Cain, Sal-
lis, Conway, Van Dyck, & Calhoon, 2013).
A valid day is one of the conditions we need to take in considera-
tion when measuring with accelerometers. The valid day is defined
by a minimum number of wearing hours. Rule 70/80 provides that
70% of the sample subjects wear an accelerometer for at least 80%
of the daily observation time (Catellier et al., 2005). Minimum num-
ber of wearing accelerometer ranges from 3–10 days (Mattocks et
al., 2008), 7 days should be reasonable standard for all ages (Ward,
Evenson, Vaughn, Rodgers, & Troiano, 2005). One of these days
needs to be weekend day (Rowlands, 2007).
When measuring physical activity with accelerometers, we need
to define non-wear time within a day, which is normally identified
with summing consecutive zero counts per minute (cpm) and wear
time is computed by decreasing the non-wear time from cumulative
possible time. It is very important to differentiate between wearing
accelerometer but being sedentary and not wearing accelerometer
because of sleep time or swimming (Cain et al., 2013).
Pedometer is probably the oldest technique to assess physical activ-
ity and was designed by Leonardo da Vinci 500 years ago (Montoye,
Kemper, Saris, & Washburn, 1996). The pedometer records acceler-
ation and deceleration of movement in one direction (Saris & Bink-
horst, 1977). Pedometers provide measure of the number of steps
taken during a given period of time (Kohl et al., 2000). Pedomet-
ers have been used for measuring physical activity for the last two
decades. Advantage of pedometers is low-cost, effectiveness (Buck-
worth, Lee, Regan, Schneider, & DiClemente, 2007) and usefulness
particularly in the epidemiological studies (Volmut, 2014). Disad-
47
